[marcAKAmarc]

Similar to your first point, I like to find parts of my life that I'm CURIOUS about, and automate them or make a model/simulation of them. This technique has the added bonus of deepening your understanding of that aspect of your life.

For example, I've been a hobbyist songwriter / composer for a good part of my life. Recently I've taken up creating a procedural musical composition generator, and boy have I learned more about music theory in the past few months than I have in the past few years. Additionally, I've gained significant insight into my own musical tendencies. Not to mention, a programming product that I'm both proud of and interested in using/improving.